U.S. patent number 5,980,455 [Application Number 08/893,066] was granted by the patent office on 1999-11-09 for method for manipulating a tissue structure within a thoracic cavity.
This patent grant is currently assigned to Heartport, Inc.. Invention is credited to S. Christopher Daniel, Robert K. Deckman, Michi E. Garrison.
United States Patent |
5,980,455 |
Daniel , et al. |
November 9, 1999 |
Method for manipulating a tissue structure within a thoracic
cavity
Abstract
A method for manipulating a tissue structure within a body
cavity provides for retracting and supporting the heart wall to
provide access into the heart during a cardiac surgical procedure.
In one embodiment of the present invention, a surgical tool support
apparatus comprises a base having an atraumatic tissue-engaging
surface and an aperture for receiving an elongate tool. The
apparatus also has a clamp assembly aligned with the aperture and
spaced-apart from a surface of the base opposite to the
tissue-engaging surface. The apparatus is particularly useful in
maintaining a retracting force on a surgical tool used to
manipulate tissue within a body cavity such as the thoracic
cavity.
Inventors: |
Daniel; S. Christopher (San
Francisco, CA), Deckman; Robert K. (San Mateo, CA),
Garrison; Michi E. (Half Moon Bay, CA) |
Assignee: |
Heartport, Inc. (Redwood City,
CA)
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Family
ID: |
27487234 |
Appl.
No.: |
08/893,066 |
Filed: |
July 15, 1997 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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577547 |
Dec 22, 1995 |
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294454 |
Aug 23, 1994 |
5613937 |
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163241 |
Dec 6, 1993 |
5571215 |
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023778 |
Feb 22, 1993 |
5452733 |
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Current U.S.
Class: |
600/235; 600/201;
600/227 |
Current CPC
Class: |
A61B
17/00234 (20130101); A61B 90/50 (20160201); A61B
17/0469 (20130101); A61B 17/06061 (20130101); A61B
18/1492 (20130101); A61F 2/2427 (20130101); A61M
39/0247 (20130101); A61B 17/0218 (20130101); A61B
17/0467 (20130101); A61B 17/2909 (20130101); A61B
17/3417 (20130101); A61B 2017/00243 (20130101); A61B
2017/00247 (20130101); A61B 2017/00349 (20130101); A61B
2017/0243 (20130101); A61B 2017/047 (20130101); A61B
2017/0472 (20130101); A61B 2017/0474 (20130101); A61B
2017/0475 (20130101); A61B 2017/2943 (20130101); A61B
2017/2946 (20130101); A61B 2017/306 (20130101); A61B
2017/3405 (20130101); A61B 2017/3425 (20130101); A61B
2017/3492 (20130101); A61B 2018/00214 (20130101); A61B
2018/00232 (20130101); A61B 2018/00261 (20130101); A61B
2018/00291 (20130101); A61B 2018/00363 (20130101); A61B
2018/00392 (20130101); A61B 2018/00577 (20130101); A61M
25/1011 (20130101); A61M 2025/028 (20130101); A61M
2039/027 (20130101); A61M 2039/0279 (20130101); A61M
2205/3344 (20130101); A61M 2205/3355 (20130101); A61M
2205/366 (20130101) |
Current International
Class: |
A61F
2/24 (20060101); A61B 17/02 (20060101); A61M
1/00 (20060101); A61B 17/34 (20060101); A61B
17/04 (20060101); A61B 17/00 (20060101); A61B
001/313 () |
Field of
Search: |
;600/201,204,210,213,226,227,228,229,230,231,232,233,234,235,215,114
;604/49,142 ;606/46 ;623/2 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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WO 93/09709 |
|
May 1993 |
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WO |
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WO 93/09720 |
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May 1993 |
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WO |
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WO 95/15715 |
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Jun 1995 |
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WO |
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Other References
Scanlan International, Inc., Surgical Instrumentation Catalog,
1992, p. 81. .
Pilling Co., Surgical Instruments Catalog, 1993, pp. 294-296. .
Omnitract Surgical Catalog, "Laparoscopic Surgery Instrumentation,"
pp. 14-16. .
Carter, M.G. "A New Retractor For Open Mitral Valve Surgery,"
Journal of Thoracic and Cardiovascular Surgery, 1962, vol. 44, No.
2..
|
Primary Examiner: Leubecker; John P.
Attorney, Agent or Firm: Grainger; Jeffry J. Hoekendijk;
Jens E.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of commonly-assigned,
co-pending application Ser. No. 08/577,547, filed Dec. 22, 1995
which is a divisional of 08/294,454, filed Aug. 23, 1994, now U.S.
Pat. No. 5,613,937, which is a continuation-in-part of application
Ser. No. 08/163,241, filed Dec. 6, 1993 now U.S. Pat. No.
5,571,215, which is a continuation-in-part of application Ser. No.
08/023,778, filed Feb. 22, 1993 now U.S. Pat. No. 5,452,733. The
complete disclosures of these applications and patents are hereby
incorporated herein by reference.
Claims
What is claimed is:
1. A method for manipulating a tissue structure within a thoracic
cavity of a patient, comprising the steps of:
providing a tissue positioning tool having a shaft, a tool support
apparatus, and a tissue supporting member, the tool support
apparatus having a clamp assembly configured to secure the shaft to
the tool support apparatus, the tool support apparatus also having
a base, the clamp assembly being pivotable relative to the
base;
positioning the tool support apparatus on an outer surface of a
patient's chest;
introducing the tissue supporting member into the patient's
thoracic cavity;
contacting a tissue structure in the thoracic cavity with the
tissue supporting member, the tissue supporting member being
coupled to the shaft;
applying a force to the shaft so that the tissue supporting member
moves the tissue structure to a displaced position; and
locking the shaft to the tool support apparatus with the clamp
assembly after the applying step so that the tissue structure
maintains the displaced position.
2. The method of claim 1, wherein the providing step is carried out
with the clamp assembly having an actuator, the actuator being
movable to a locked position which secures the shaft relative to
the tool support apparatus, the actuator also fixing an angular
orientation of the clamp assembly relative to the base when moved
to the locked position thereby preventing pivoting of the clamp
assembly relative to the base.
3. The method of claim 1, wherein the locking, applying,
contacting, introducing and positioning steps are carried out with
only the shaft penetrating the patient's chest and the tool support
apparatus engaging only the outer surface of the patient's
chest.
4. The method of claim 1, wherein the providing step is carried out
with the tool support apparatus having a base, the base having a
bottom surface having a surface area of at least 3 square
inches.
5. The method of claim 1, wherein:
the providing step is carried out with the tool support apparatus
having an elastomeric cushion; and
the positioning step is carried out with the elastomeric cushion
engaging the outer surface of the patient's chest.
6. A method for manipulating a tissue structure within a thoracic
cavity of a patient, comprising the steps of:
providing a tissue positioning tool having a shaft, a tool support
apparatus, and a tissue supporting member, the tool support
apparatus having a clamp assembly configured to secure the shaft to
the tool support apparatus;
positioning the tool support apparatus on an outer surface of a
patient's chest;
introducing the tissue supporting member into the patient's
thoracic cavity;
contacting a tissue structure in the thoracic cavity with the
tissue supporting member, the tissue supporting member being
coupled to the shaft;
applying a force to the shaft so that the tissue supporting member
moves the tissue structure to a displaced position; and
locking the shaft to the tool support apparatus with the clamp
assembly after the applying step so that the tissue structure
maintains the displaced position;
the introducing step being carried out with the tissue supporting
member passing through a first opening in the patient's chest;
and
the applying step being carried out with the shaft passing through
a second opening in the patient's chest.
7. The method of claim 6, wherein the providing step is carried out
with the tool support apparatus having a base, the clamp assembly
being pivotable relative to the base.
8. The method of claim 6, further comprising the step of:
attaching the tissue supporting member to the shaft within the
patient's chest.
9. A method for manipulating a tissue structure within a thoracic
cavity of a patient, comprising the steps of:
providing a tissue positioning tool having a shaft, a tool support
apparatus, and a tissue supporting member, the tool support
apparatus having a clamp assembly configured to secure the shaft to
the tool support apparatus, the tool support apparatus also having
a base, the base having a bottom surface having a surface area of
at least 3 square inches and a maximum outer dimension of no more
than 3.5 inches;
positioning the tool support apparatus on an outer surface of a
patient's chest;
introducing the tissue supporting member into the patient's
thoracic cavity;
contacting a tissue structure in the thoracic cavity with the
tissue supporting member, the tissue supporting member being
coupled to the shaft;
applying a force to the shaft so that the tissue supporting member
moves the tissue structure to a displaced position; and
locking the shaft to the tool support apparatus with the clamp
assembly after the applying step so that the tissue structure
maintains the displaced position.
10. The method of claim 9, wherein the providing step is carried
out with the bottom surface having a circular shape with a radial
slot.
11. A method of retracting a tissue structure, comprising the steps
of:
providing a tissue positioning tool having a shaft and a tissue
supporting member;
introducing the tissue supporting member into the patient through a
first penetration in the patient;
introducing the shaft through a second penetration in the
patient;
attaching the tissue supporting member to the shaft within the
patient;
contacting a tissue structure in the patient with the tissue
supporting member; and
applying a force to the shaft so that the tissue supporting member
moves the tissue structure to a displaced position.
12. The method of claim 11, wherein the providing step is carried
out with the tissue positioning tool including a tool support
apparatus.
13. The method of claim 12, further comprising the steps of:
positioning the tool support apparatus on an outer surface of a
patient's chest; and
locking the shaft to the tool support apparatus after the applying
step so that the tissue structure maintains the displaced position.
Description
BACKGROUND OF THE INVENTION
This invention relates generally to instruments and techniques for
performing less-invasive surgical procedures, and more
specifically, to less-invasive instruments and techniques for
retracting tissue structures within body cavities such as the
abdomen or thorax.
Various types of surgical procedures are currently performed to
investigate, diagnose, and treat diseases of the heart and the
great vessels of the thorax. Such procedures include repair and
replacement of mitral, aortic, and other heart valves, repair of
atrial and ventricular septal defects, pulmonary thrombectomy,
treatment of aneurysms, electrophysiological mapping and ablation
of the myocardium, and other procedures in which interventional
devices are introduced into the interior of the heart or a great
vessel.
Using current techniques, many of these procedures require a gross
thoracotomy, usually in the form of a median sternotomy, to gain
access into the patient's thoracic cavity. A saw or other cutting
instrument is used to cut the sternum longitudinally, allowing two
opposing halves of the anterior or ventral portion of the rib cage
to be spread apart. A large opening into the thoracic cavity is
thus created, through which the surgical team may directly
visualize and operate upon the heart and other thoracic
contents.
Surgical intervention within the heart generally requires isolation
of the heart and coronary blood vessels from the remainder of the
arterial system, and arrest of cardiac function. Usually, the heart
is isolated from the arterial system by introducing an external
aortic cross-clamp through a sternotomy and applying it to the
aorta between the brachiocephalic artery and the coronary ostia.
Cardioplegic fluid is then injected into the coronary arteries,
either directly into the coronary ostia or through a puncture in
the aortic root, so as to arrest cardiac function. In some cases,
cardioplegic fluid is injected into the coronary sinus for
retrograde perfusion of the myocardium. The patient is placed on
cardiopulmonary bypass to maintain peripheral circulation of
oxygenated blood.
Of particular interest to the present invention are intracardiac
procedures for surgical treatment of heart valves, especially the
mitral and aortic valves. According to recent estimates, more than
79,000 patients are diagnosed with aortic and mitral valve disease
in U.S. hospitals each year. More than 49,000 mitral valve or
aortic valve replacement procedures are performed annually in the
U.S., along with a significant number of heart valve repair
procedures.
Various surgical techniques may be used to repair a diseased or
damaged valve, including annuloplasty (contracting the valve
annulus), quadrangular resection (narrowing the valve leaflets),
commissurotomy (cutting the valve commissures to separate the valve
leaflets), shortening mitral or tricuspid valve chordae tendonae,
reattachment of severed mitral or tricuspid valve chordae tendonae
or papillary muscle tissue, and decalcification of valve and
annulus tissue. Alternatively, the valve may be replaced, by
excising the valve leaflets of the natural valve, and securing a
replacement valve in the valve position, usually by suturing the
replacement valve to the natural valve annulus. Various types of
replacement valves are in current use, including mechanical and
biological prostheses, homografts, and allografts, as described in
Bodnar and Frater, Replacement Cardiac Valves 1-357 (1991), which
is incorporated herein by reference. A comprehensive discussion of
heart valve diseases and the surgical treatment thereof is found in
Kirklin and Barratt-Boyes, Cardiac Surgery 323-459 (1986), the
complete disclosure of which is incorporated herein by
reference.
The mitral valve, located between the left atrium and left
ventricle of the heart, is most easily reached through the wall of
the left atrium, which normally resides on the posterior side of
the heart, opposite the side of the heart that is exposed by a
median sternotomy. Therefore, to access the mitral valve via a
sternotomy, the heart is rotated to bring the left atrium into an
anterior position accessible through the sternotomy. An opening, or
atriotomy, is then made in the right side of the left atrium,
anterior to the right pulmonary veins. The atriotomy is retracted
by means of sutures or retraction devices, exposing the mitral
valve directly posterior to the atriotomy. One of the
aforementioned techniques may then be used to repair or replace the
valve.
An alternative technique for mitral valve access may be used when a
median sternotomy and/or rotational manipulation of the heart are
undesirable. In this technique, a large incision is made in the
right lateral side of the chest, usually in the region of the
fourth intercostal space. One or more ribs may be removed from the
patient, and other ribs near the incision are retracted outward to
create a large opening into the thoracic cavity. The left atrium is
then exposed on the posterior side of the heart, and an atriotomy
is formed in the wall of the left atrium, through which the mitral
valve may be accessed for repair or replacement.
Using such open-chest techniques, the large opening provided by a
median sternotomy or right thoracotomy enables the surgeon to see
the mitral valve directly through the left atriotomy, and to
position his or her hands within the thoracic cavity in close
proximity to the exterior of the heart for manipulation of surgical
instruments, removal of excised tissue, and/or introduction of a
replacement valve through the atriotomy for attachment within the
heart. However, these invasive, open-chest procedures produce a
high degree of trauma, a significant risk of complications, an
extended hospital stay, and a painful recovery period for the
patient. Moreover, while heart valve surgery produces beneficial
results for many patients, numerous others who might benefit from
such surgery are unable or unwilling to undergo the trauma and
risks of current techniques.
In response to the various problems associated with open-chest
procedures, new methods of performing closed-chest surgery on the
heart using minimally invasive thoracoscopic techniques have been
recently developed. In these methods, the patient's heart is
arrested by occluding the patient's aorta between the coronary
arteries and the brachiocephalic artery with an expandable balloon
on the distal end of an endovascular catheter introduced via a
femoral artery. Cardioplegic fluid is then delivered to the
patient's myocardium through a lumen in the same catheter or
through a catheter positioned in the coronary sinus via a
peripheral vein. To repair or replace the mitral valve,
minimally-invasive cutting and suturing instruments are then
introduced thoracoscopically through a trocar sleeve in the right
lateral portion of the chest. A complete description of such
methods is found in commonly assigned, co-pending application Ser.
No. 08/163,241, filed Dec. 6, 1993, now U.S. Pat. No. 5,571,215
which has been previously incorporated herein by reference.
This new generation of thoracoscopic methods of performing heart
valve repair has, of course, created many new challenges. One such
challenge is that of retracting the left atrial wall to open the
atriotomy so that the mitral valve can be exposed for the surgical
procedure. The heart wall must be retracted anteriorly to suitably
expose the mitral valve and provide access through the atriotomy
for the cutting and suturing instruments introduced through the
right lateral portion of the chest. In addition, the instruments
that retract the heart wall must be introduced in a
minimally-invasive manner through small percutaneous incisions or
cannulae positioned in intercostal spaces in the patient's rib
cage.
Introducing an instrument through an intercostal space in the
anterior side of the chest presents additional problems. One such
problem is that the patient's rib cage is typically structured so
that the ribs in the anterior portion of the chest are closer
together than in the lateral portions of the chest. In addition,
the tissue layer in the anterior chest wall contains nerves that
could be damaged by a large percutaneous incision. Therefore, a
retraction device introduced from the anterior side should be as
small as possible, preferably on the order of 3-8 mm, to fit within
the smaller anterior intercostal spaces and to avoid unnecessary
trauma to the patient. Another problem is that the part of the
retraction device that engages the heart wall must be wide enough
to engage a sufficient portion of the heart wall to open the
atriotomy enough to expose the mitral valve. It must also be long
enough to extend a sufficient distance into the heart to extend
beneath the interatrial septum and prevent it from sagging or
otherwise inhibiting access to the mitral valve. Introducing an
instrument which is large enough to sufficiently expose the mitral
valve through the smaller intercostal spaces in the anterior
portion of the chest is problematic.
Additionally, portions of the heart wall are typically retracted
for a substantial period of time during the mitral valve
replacement procedure. Conventionally, retraction is maintained by
a nurse or surgeon physically holding a retractor in position for
the duration of time required. Alternatively, some surgeons have
jerry-rigged scissor clamps or other devices to hold the retractor
in position during surgery. The first approach is an inefficient
use of resources, and the second creates a dangerous situation
should one of the jury-rigged clamps fail. These approaches also
fail to provide a reliable and consistently stable retraction of
heart tissue as required during such delicate interventional
procedures. Although some large, floor-based positioning devices
exist that have an arm extending from the floor up and over the
patient, they fail to provide the ease of removal and compact
configuration required in the close quarters of the operating area.
The larger devices tend to retract laterally when the device cannot
be positioned directly over the site of retraction and are
difficult to remove if fluoroscopy or other diagnostic procedures
need to be performed during the course of valve replacement.
What is needed, therefore, are improved apparatus, systems, and
methods for manipulating a tissue structure in a body cavity via a
small percutaneous penetration or cannula. Particularly, the
apparatus, systems, and methods should be capable of providing
constant and reliable retraction of tissue in the thoracic cavity
during delicate and sensitive procedures such as mitral valve
replacement. The apparatus would preferably be of compact design,
being easily deployable, adjustable, and removable from the
patient, while providing constant, reliable retraction without
requiring the services of a nurse or doctor to maintain retracting
force.
SUMMARY OF THE INVENTION
The present invention provides apparatus, systems, and methods for
manipulating a tissue structure in a body cavity through a small
percutaneous penetration in a patient. The system is preferably
configured for use with a small percutaneous penetration into a
body cavity and for retracting an incision in the left atrium from
the anterior side of the chest. The system is well suited for
providing constant and reliable retraction of the heart wall,
making the invention particularly useful during surgeries such as
mitral valve replacement. While being especially useful for
thoracoscopy, the present invention is also useful in other
surgical procedures, such as laparoscopy and pelviscopy.
According to the present invention, a method for manipulating
tissue structure within the thoracic cavity of a patient comprises
the step of introducing a tissue positioning tool having a shaft
into the thoracic cavity through a percutaneous penetration. A
force is applied to the shaft to engage the tissue structure with
the tissue positioning tool, so as to reposition the tissue
structure within the thoracic cavity. A tool support apparatus is
positioned on an outer surface of the thoracic cavity. The
positioning of the tool support apparatus may occur prior to or
after the introduction of the tool into the cavity. With the
desired force applied to the shaft, the shaft of the tissue
positioning tool is fixedly secured to the support apparatus. The
force to the shaft is maintained against the repositioned tissue
structure through contact of the tool support apparatus against an
outer surface of the thoracic cavity.
In one embodiment of the present invention, the method comprises a
positioning step where a base of the support apparatus is rested
tangentially on the outer surface of the thoracic cavity. To
facilitate engagement of the apparatus with the shaft of the
positioning tool, a clamp assembly of the support apparatus is
aligned with a longitudinal axis of the shaft. The base is
preferably positioned so that an aperture in the base rests
directly over the percutaneous penetration. This allows the support
apparatus to provide retraction in a direction normal to the outer
surface of the cavity. It should be understood, however, that the
support apparatus can provide retraction at a variety of different
angles and is not limited to retraction at angles perpendicular to
the surface of the cavity.
In another embodiment of the present invention, the introduction
step of the method comprises introducing a tissue supporting member
having a contact surface into the thoracic cavity through a first
percutaneous penetration. The shaft of the tool, having a
longitudinal axis, is introduced through a second percutaneous
penetration. The tissue supporting member is connected to the shaft
within the thoracic cavity to form a tissue positioning tool.
Assembling the tool within the thoracic cavity allows the use of
positioning devices having parts and surfaces too large to be
introduced through the typically smaller penetration from which the
shaft of the tool extends.
According to the present invention, a surgical tool support
apparatus comprises a base having an atraumatic tissue-engaging
surface and an aperture for receiving an elongate tool. The
apparatus also has a clamp assembly aligned with the aperture and
spaced-apart from a surface of the base opposite to the
tissue-engaging surface.
In one embodiment of the invention, the apparatus comprises a base
having a rigid plate and a biocompatible elastomeric cushion over
the atraumatic surface for minimizing pressure trauma to the
patient. The cushion may be removably attached to the rigid plate.
Having the cushion and other parts of the invention removable from
each other facilitates cleaning and replacement of the parts of the
apparatus.
In another embodiment of the invention, the clamp assembly of the
apparatus is rotatably attached to the base about an axis generally
parallel to the atraumatic tissue-engaging surface. The clamp
assembly typically comprises a pair of jaws where at least one of
the jaws has a flange extending from a surface of the jaw to
facilitate alignment when the jaws close. The clamp assembly also
has a closing mechanism for bring the pair of jaws into
contact.
According to the present invention, a system for manipulating
tissue structure within the thoracic cavity comprises a linking
member, a first clamp, and a second clamp. The first clamp has a
first jaw and a second jaw where the first jaw is movably coupled
to the second jaw by the linking member. The second clamp is
mounted on the second jaw of the first clamp for fixedly engaging
the linking member. The second clamp is preferably has a rotational
linkage for rotatably coupling the second jaw to the linking
member.
In a further aspect of the present invention, a kit of the present
invention comprises a base having an atraumatic tissue-engaging
surface and an aperture for receiving an elongate tool. The kit
also has a clamp assembly aligned with the aperture and
spaced-apart from a surface of the base opposite to the
tissue-engaging surface. Instructions for use setting forth a
method of the present invention are enclosed in a package along
with the base and the clamp assembly. A retractor or tissue
positioning tool may also be included in the package.
It should be understood that while the invention is described in
the context of thoracoscopic surgery on the left atrium and mitral
valve, the systems and methods disclosed herein are equally useful
on other types of tissue structures and in other types of surgery,
such as laparoscopy and pelviscopy.
A further understanding of the nature and advantages of the
invention may be realized by reference to the remaining portions of
the specification and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a closed-chest mitral valve
replacement using minimally invasive techniques and a
retractor;
FIG. 2 is a front view of the procedure of FIG. 1, showing the
positioning of the surgical instruments in the patient's chest;
FIG. 3 is a front view of a patient's cardiovascular system
illustrating the positioning of a system for arresting the heart
and establishing cardiopulmonary bypass in accordance with
closed-chest mitral valve replacement;
FIG. 4A is a top view looking into the patient's thoracic cavity
through a passage of an access cannula in the system of FIG. 1,
showing the creation of an atriotomy in the patient's left
atrium;
FIG. 4B is a transverse cross-sectional view of the patient of FIG.
1 taken through the patient's thorax, showing the introduction of
the replacement valve into the left atrium and the tying of knots
in the sutures to secure a prosthesis in the patient's heart;
FIG. 5A is a perspective view of the support apparatus constructed
in accordance with the principals of the present invention;
FIG. 5B is a perspective view of the cushion of the apparatus of
FIG. 5A;
FIG. 5C is a perspective view of the base and L-shaped arm of the
apparatus of FIG. 5A;
FIGS. 6A-6C are overhead perspective views of the apparatus of FIG.
5A fitted with a variety of clamp assembly closure devices;
FIGS. 6D-6E are perspective views of the jaws used in the clamp
assembly of the apparatus of FIG. 5A;
FIG. 7A is a perspective view of the system of the present
invention;
FIG. 7B is cross-sectional view of a portion of the thoracic cavity
with a retractor of the system of FIG. 7A exiting the cavity at a
non-perpendicular angle and coupled to the support apparatus of the
system;
FIGS. 8-9 is a transverse cross-sectional view of the patient of
FIG. 1 taken through the patient's thorax, showing the assembly of
a retractor or tissue positioning tool and the use of the tool with
a tool support apparatus;
FIG. 10 is a perspective view of a closed-chest mitral valve
replacement using minimally invasive techniques, a retractor, and a
tool support apparatus of the present invention;
FIGS. 11A-11B are perspective views of alternate embodiments of a
tool support apparatus of the present invention; and
FIG. 12 shows a kit of the present invention containing a tissue
positioning tool, a tool support apparatus of the present
invention, and instructions for use in accordance with a method of
the present invention.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
I. Introduction
The invention provides methods and devices for facilitating
surgical interventions within body cavities such as the thoracic
cavity. While the specific embodiments of the invention described
herein will refer to mitral valve repair and replacement, it should
be understood that the invention will be useful in performing
retraction for a great variety of surgical procedures, including
repair and replacement of aortic, tricuspid, or pulmonary valves,
repair of atrial and ventricular septal defects, pulmonary
thrombectomy, removal of atrial myxoma, patent foramen ovale
closure, treatment of aneurysms, electrophysiological mapping and
ablation of the myocardium, myocardial drilling, coronary artery
bypass grafting, angioplasty, atherectomy, correction of congenital
defects, and other procedures in which interventional devices are
introduced into the interior of body cavities such as the thoracic
cavity.
The present invention is of particular use in minimally invasive
procedures performed in the chest through percutaneous intercostal
penetrations. The terms "percutaneous intercostal penetration" and
"intercostal penetration" as used herein refer to a penetration, in
the form or a small cut, incision, hole, cannula, trocar sleeve, or
the like, through the chest wall between two adjacent ribs, wherein
the patient's rib cage and sternum remain substantially intact,
without cutting, removing, or significantly displacing the ribs or
sternum. These terms are intended to distinguish a gross
thoracotomy such as a median sternotomy, wherein the sternum and/or
one or more ribs are cut or removed from the rib cage, or one or
more ribs are retracted significantly, to create a large opening
into the thoracic cavity. A "percutaneous intercostal penetration"
may abut or overlap the adjacent ribs between which it is formed,
but the maximum width of the penetration which is available for
introduction of instruments, prostheses and the like into the
thoracic cavity will be the width of the intercostal space, bounded
by two adjacent ribs in their natural, substantially undeflected
positions. It should be understood that one or more ribs may be
retracted or deflected a small amount without departing from the
scope of the invention; however, the invention specifically seeks
to avoid the pain, trauma, and complications which result from the
large deflection or cutting of the ribs in conventional, open-chest
techniques.
Advantageously, the present invention facilitates the performance
of procedures using percutaneous penetrations within intercostal
spaces of the rib cage to obviate the need for a median sternotomy
or other form of gross thoracotomy. The present invention is of
particular use in closed-chest mitral valve replacement.
II. Overview of a Closed-Chest Mitral Valve Replacement
A method for performing closed-chest mitral valve replacement will
be described with reference to FIGS. 1-10. FIG. 1 illustrates a
system 20 for closed-chest valve replacement positioned in a
patient P on an operating table T. Preferably, a wedge or block W
having a top surface angled at approximately 20.degree. to
45.degree. is positioned under the right side of patient P so that
the right side of the patient's body is somewhat higher than the
left side. The patient's right arm A is allowed to rotate downward
to rest on table T, exposing the right lateral side of the
patient's chest.
The valve replacement system 20 includes an access cannula 22
positioned percutaneously within an intercostal space between two
ribs (shown in phantom) in a right lateral side of the patient's
chest. Additional thoracoscopic trocar sleeves 24 of conventional
construction are positioned within intercostal spaces in the right
lateral chest inferior and superior to access cannula 22, as well
as in the right anterior (or ventral) portion of the chest. An
endoscope 25 of conventional construction is positioned through a
percutaneous intercostal penetration into the patient's chest,
usually through one of trocar sleeves 24. The distal end of
endoscope 25 (shown in phantom) is preferably configured to view at
an angle between about 30.degree. and 90.degree. relative to the
shaft of endoscope 25, to facilitate visualization of the heart
from the right portion of the thoracic cavity. A light source (not
shown) is also provided on endoscope 25 to illuminate the thoracic
cavity. A video camera 26 is mounted to the proximal end of
endoscope 25, and is connected to a video monitor 28 for viewing
the interior of the thoracic cavity. A first suture organizing ring
30 is mounted to a proximal end of access cannula 22. A second
organizing ring 32 is mounted to a support stand 34 fixed to table
T. A replacement valve 36 is held at the distal end of an
introducer 38 between first organizing ring 30 and second
organizing ring 32. Introducer 38 extends through second organizing
ring 32 and is supported by support stand 34. Additional
instruments to be used in a procedure such as a retractor 40, as
well as cutting, suturing, stapling, aspirating, irrigating and
other devices, may be introduced through access cannula 22, trocar
sleeves 24, and/or small, percutaneous incisions within intercostal
spaces of the rib cage.
Referring now to FIG. 2, access cannula 22 is positioned within an
intercostal space I in the right lateral side of the chest,
preferably in the third, fourth, fifth, or sixth intercostal space
between adjacent ribs R. Additional trocar sleeves 24A, 24B are
positioned within intercostal spaces superior and inferior to
access cannula 22 in the right lateral side of the chest. Access
cannula 22 and trocar sleeves 24A, 24B are positioned so that
instruments 42 introduced through them may be directed toward the
right side of the left atrium of the heart H. A trocar sleeve 24C
is positioned in an intercostal space in the right anterior side of
the chest such that endoscope 25 may be introduced to view the
thoracic cavity and heart H without interfering with instruments
introduced through access cannula 22 or trocar sleeves 24A, 24B. An
additional trocar sleeve 24D is positioned in an intercostal space
in the anterior side of the chest just to the right of the sternum
and anterior to the right lateral side of the heart H.
It will be understood to those of ordinary skill in the art that,
in some cases, it may desirable to eliminate some or all of trocar
sleeves 24 and/or access cannula 22, and introduce instruments
directly through small, percutaneous intercostal incisions in the
chest. Advantageously, unlike laparoscopic, arthroscopic, and other
endoscopic procedures, no distension of the chest is required using
the method of the invention, so that leakage of distension fluid
through percutaneous penetrations is not of concern. Thus, either
thoracoscopic trocar sleeves without fluid seals or percutaneous
incisions may be utilized for instrument introduction into the
thoracic cavity. Trocar sleeves are generally preferred, however,
in order to provide an open passage into the thoracic cavity, to
protect adjacent tissue from injury resulting from contact with
instruments, and to avoid damaging instruments, endoscopes,
replacement valves, and the like when introduced into the thoracic
cavity.
Referring again to FIG. 2, once access cannula 22 and trocar
sleeves 24 have been positioned in the patient's chest, endoscope
25 is introduced through trocar sleeve 24D and camera 26 is
connected to video monitor 28 (FIG. 1). Endoscope 25 is manipulated
so as to provide a view of the right side of the heart, and
particularly, a right side view of the left atrium. Usually, an
endoscope of the type having an articulated distal end, or a distal
end disposed at an angle between 30.degree. and 90.degree. will be
used, which is commercially available from, for example, Olympus
Corp., Medical Instruments Division, Lake Success, N.Y.
At this point in the procedure, if not previously accomplished, the
patient is placed on cardiopulmonary bypass (CPB), the patient's
right lung is at least partially collapsed, and the patient's heart
is arrested. Suitable techniques for arresting cardiac function and
establishing CPB without a thoracotomy are described in
commonly-assigned, co-pending applications Ser. No. 07/991,188,
filed Dec. 15, 1992, and Ser. No. 08/123,411, filed Sep. 17, 1993
(Attorney Docket No. 14635-4/93002-1), both of which are
incorporated herein by reference.
As illustrated in FIG. 3, CPB is established by introducing a
venous cannula 70 into a femoral vein 72 in patient P and advancing
venous cannula 72 into the inferior vena cava 74 and/or into the
interior of heart H to withdraw deoxygenated blood therefrom.
Venous cannula 70 is connected to a cardiopulmonary bypass system
76 which receives the withdrawn blood, oxygenates the blood, and
returns the oxygenated blood to an arterial return cannula 78
positioned in a femoral artery 80. The right lung may also be
collapsed at this time and cardiac function arrested using known
techniques. Usually, a tube is introduced through the trachea into
the right main stem bronchus, and a vacuum is applied through the
tube to collapse the lung. Suitable methods for performing the
above procedures may be found in commonly assigned, co-pending
application Ser. No. 08/577,547, filed Dec. 22, 1995 (Attorney
Docket No. 14635-002810), the complete disclosure of which has been
previously incorporated herein by reference.
With cardiopulmonary bypass established, cardiac function arrested,
and the right lung collapsed, the patient is prepared for surgical
intervention within the heart H. Referring again to FIG. 2, a
surgical cutting instrument such as angled scissors 110, as well as
a grasping instrument such as grasping forceps 112, are introduced
through access cannula 22 or through trocar sleeves 24A, 24B.
Angled scissors 110 and forceps 112 are used to form an opening in
the pericardium, providing access to the right side of the left
atrium.
FIG. 4A illustrates the view into the thoracic cavity through
passage 50 of access cannula 22. Angled scissors 110 aided by
grasping forceps 112 are shown cutting through the right side of
left atrium LA to form an atriotomy 162. Atriotomy 162 is formed
along dotted line 164 anterior to right pulmonary veins PV. A
completed description of techniques for forming such an atriotomy
is found in Kirklin and Barratt-Boyes, Cardiac Surgery, pp.
329-340, the disclosure of which has been incorporated herein by
reference. Usually, atriotomy 162 will be formed under
visualization by means of endoscope 25 (FIGS. 1 and 2), although
direct viewing is possible through passage 50 of access cannula 22,
or through a trocar sleeve 24.
Upon completion of atriotomy 162, the wall of left atrium LA on the
anterior side of atriotomy 162 is retracted anteriorly by means of
thoracoscopic retractor 40, as illustrated in FIG. 1. A variety of
retractors 40 may be used and details on a suitable retractor for
use with the present invention may be found in commonly assigned,
co-pending application Ser. No. 08/577,547, filed Dec. 22, 1995
(Attorney Docket No. 14635-002810), the complete disclosure of
which has been previously incorporated herein by reference.
Retractor 40 is pulled in the anterior direction to retract the
wall of left atrium LA, opening atriotomy 162 and exposing the
patient's mitral valve MV within the left atrium LA.
Referring to FIG. 4B, retractor 40 is positioned so that tissue
supporting member 500 is oriented with contact surface 502
extending towards the atriotomy in the left atrium LA. The surgeon
then manipulates handle 412 to position tissue supporting member
500 in the atriotomy 162 so that the outer atrium wall AW is on
contact surface 502. Once tissue supporting member 500 is in the
desired position, the surgeon pulls retractor 40 proximally to
retract atrium wall AW anteriorly, as shown in FIG. 4B. Tissue
supporting member 500 preferably extends deeply into the left
atrium LA so that the interatrial septum S is effectively supported
on contact surface 502.
At this point, with atriotomy 162 retracted open, the mitral valve
MV is exposed for an approach from the right lateral side of the
chest via access cannula 22. Instruments may be introduced into the
interior of the heart H through access cannula 22 or trocar sleeves
24. The instruments may extend through the atriotomy 162 to perform
a procedure within the left atrium LA or may alternatively extend
further through the mitral valve MV to gain access to the aortic
valve in the left ventricle.
Replacement of the mitral valve MV typically comprises cutting or
removal of all or part of the mitral valve leaflets VL. Once the
valve leaflets are removed or reduced, it is usually necessary to
size the valve annula VA so as to select a replacement valve 36 of
proper size for patient P. Various methods and devices may be used
for sizing the valve for replacement. As shown more clearly in FIG.
4B, with the correct valve selected, the replacement valve 36 is
introduced into the left atrium and sutured to an annulus at the
natural valve position in the heart. Replacement valve 36 may then
be introduced into the left atrium LA by advancing introducer 38
through passage 50 of access cannula 22. Replacement valve 36 is
oriented on introducer 38 so as to be introduced edge-first through
passage 50. As replacement valve 36 is advanced into the thoracic
cavity, organizing ring 32 maintains tension on sutures 198,
allowing replacement valve 36 to slide along sutures 198.
Introducer 38 is advanced through atriotomy 162 so that replacement
valve 36 is disposed within left atrium LA. Replacement valve 36 is
positioned against or within valve annulus VA. Square or overhand
knots are then formed in sutures 198 outside of the patient's
thoracic cavity, and the knots are pushed by a knot pusher 316
through passage 50 and atriotomy 162 toward sewing ring 228 of
replacement valve 36. Suitable procedures for repair or replacement
of the mitral valve may be found in commonly assigned, co-pending
application Serial No. 08/577,547, filed Dec. 22, 1995 (Attorney
Docket No. 14635-002810), the complete disclosure of which has been
previously incorporated herein by reference.
After the mitral valve MV has been repaired or replaced, the above
method is reversed to remove tissue supporting member 500 from the
patient's thoracic cavity. The atrium wall AW is disengaged from
contact surface 502 and tissue supporting member 500 is removed
from the atriotomy. After atriotomy 162 has been closed, any
remaining instruments are removed from the thoracic cavity. A chest
tube may be introduced through one of the trocar sleeves 24 to
facilitate evacuation of the pleural cavity. Access cannula 22 and
trocar sleeves 24 are then removed from the chest wall, and the
incisions or penetrations through which they were introduced are
closed, usually by suturing or stapling.
The patient's lung may then be reinflated, and cardiac function may
be restarted. As described in co-pending application Ser. No.
07/991,188, which has been incorporated herein by reference,
infusion of cardioplegic fluid through aortic occlusion catheter 82
and/or retroperfusion catheter 102 is discontinued, and a saline
solution is infused through one or both of these catheters to
irrigate the heart and coronary arteries (see FIG. 3). The saline
solution, along with blood, other fluids, air, thrombus, and other
emboli within the heart or coronary arteries are then aspirated
through the inner lumen of aortic occlusion catheter 82, as well as
through venous cannula 70 and/or pulmonary venting catheter 79.
Occlusion balloon 88 on aortic occlusion catheter 82 is then
deflated, allowing warm, oxygenated blood to flow into the coronary
arteries to perfuse the myocardium. Cardiac contractions will
usually begin soon thereafter. In some cases, electrical
defibrillation may be necessary to help restore cardiac function.
Aortic occlusion catheter 82 and retroperfusion catheter 102 may
then be removed from the patient. Cardiopulmonary bypass is then
discontinued, and arterial cannula 78, venous cannula 70, and
pulmonary venting catheter 79 are removed from the patient.
The above description is mainly for illustrative purposes, and
other surgical procedures such as repair and replacement of aortic,
tricuspid, or pulmonary valves, repair of atrial and ventricular
septal defects, or the like may be employed with the present
invention discussed below.
III. Tool Support Apparatus
Referring now to FIGS. 5-10, a surgical tool support apparatus of
the present invention for use with a retractor 40, as mentioned
above, will now be described. Although the tissue support apparatus
200 is described in the context of a mitral valve replacement
procedure, it should be understood that the surgical tool support
apparatus 200 may be used with a variety of other surgical
interventional procedures performed in the thoracic cavity. During
a typical mitral valve replacement procedure, cardiac tissue in the
area of the left atrium may need to be retracted anteriorly to
expose the mitral valve for a period of between about 30-90
minutes, typically between about 45-60 minutes. During this time
period, it is desirable that the retractor 40 pull only in the
anterior direction and not a combination of an anterior and lateral
retraction. The position of retractor 40 during the period of
anterior retraction should be maintained in a relatively constant
manner so as to brace heart wall and cardiac tissue to provide a
clear line of sight and access during this surgical procedure. As
may occur during the course of mitral valve replacement, it may
become necessary to remove the retractor 40 from the thoracic
cavity to perform fluoroscopy or other surgical procedures which
may require unobstructed access to the thoracic cavity or use of
the trocar (puncture) occupied by the retractor 40.
Conventionally, retraction of the left atrium LA in an anterior
fashion has been performed by an surgical assistant or scrub nurse
who physically holds the retractor in the desired position for the
duration of the valve replacement procedure or a portion thereof.
Alternatively, it has been observed that surgeons use clamps or
other collar mechanisms to implement a rudimentary locking device
to prevent the shaft of the retractor 40 from moving in the distal
direction during the operation. The present invention assists the
cardiothoracic surgeon by providing an apparatus that replaces
rudimentary locking devices used in a jerry-rigged or stop-gap
fashion, while providing an easily removable and atraumatic
positioning device for the retractor. The present invention has a
compact configuration that will not further clutter the area of the
surgical procedure. The invention also provides cost efficiencies
arising from reduced manufacturing and material costs associated
with its compact configuration.
Referring to FIG. 5A, a preferred embodiment of the surgical tool
support apparatus 200 comprises a base 210 and a clamp assembly 212
removably coupled to the base 210 by an L-shaped arm 214 (FIG. 5C).
Arm 214, of course, may be of other configurations as necessary to
properly position clamp assembly 212. Alternatively, the assembly
212 may be rotatably attached to the base 210 without the use of an
arm 214. As shown, the base 210 typically comprises a rigid plate
215 formed from a non-corrosive, surgically compatible material
such as surgical-grade stainless steel (303 stainless steel) or
aluminum. The material should be able to withstand autoclaving and
other types of sterilizing procedures so that the tool support
apparatus 200 may be cleaned and reused. All parts on the apparatus
200 may also be disassembled to facilitate sterilization.
As shown more clearly in FIG. 5B-5C, the base 210 has an aperture
216 for receiving a shaft of the retractor 40. The aperture 216
facilitates engagement and alignment of clamps assembly 212 with
the shaft of the retractor 40, and it should be understood that the
aperture 216 may be a circular or closed path opening in the base
or a slit, notch-like opening extending to an outer edge of the
base 210 as shown in FIG. 5A.
Referring to FIGS. 5A-5B, the base 210 of the present invention has
an atraumatic tissue-engaging surface 220. The surface 220 may be
located directly on rigid plate 215. Preferably, base 210 comprises
the rigid plate 215 and a biocompatible elastomeric cushion 222
coupled to the plate. The surface 220 would then be located on the
cushion 222. Cushion 222 has a cushion aperture 223 (FIG. 5B)
corresponding to the aperture 216, and the cushion generally
mirrors the outline of rigid plate 215. The maximum outer dimension
of the tissue-engaging surface 220 is preferably no more than about
2 inches, more preferably no more than about 2.5 inches, and most
preferably no more than about 3.5 inches. This maximum outer
dimension is in reference to maximum outer diameter for disc-shaped
surfaces or maximum horizontal width for surfaces of other
configurations. The tissue-engaging surface 200 preferably has a
surface area of at least about 3 square inches, more preferably at
least 4 square inches, and most preferably at least 5 square
inches. The tissue-engaging surface 220 of the support apparatus
200 lies on the surface of the patient's chest so that only the
shaft passes into the patient's chest thereby minimizing trauma to
the patient.
The elastomeric cushion 222 may be formed from a variety of
materials such as 20 durometer silicone, with the understanding
that the material will not agitate the area of the patient on which
the tool support apparatus 200 rests. Preferably the elastomeric
cushion 222 will also provide frictional resistance so as to
provide a stable and relatively slip-resistant grip on the surface
of the patient. The elastomeric cushion 222 may be integrally
formed with the rigid plate 215 of the base 210, wherein the rigid
plate provides structural support while the cushion 222 allows for
the typically softer cushion 220. Alternatively, as shown in FIG.
5A, the elastomeric cushion 222 may have a plurality of protrusions
224 which frictionally engage a plurality of detents or
through-holes 226 in the rigid plate of base 210 so that the
cushion may be removably coupled to the rigid plate. It should be
understood that other releasable engagement devices such as velcro
or other detent/protrusion assemblies may be used to releasably
couple the cushion 222 and the rigid plate 215.
In addition to being made preferably of biocompatible and
frictional, high-traction material, the atraumatic tissue-engaging
surface of the base 210 also has sufficient surface area so as not
to induce a pressure sore or bruise on the patient while the
retractor 40 and the tool support apparatus 200 are used. In
retracting the left atrium LA during mitral valve MV replacement,
the force encountered by the retractor 40 is between about 0.5 and
5 pounds, more typically between about 1-3 pounds. Pressures
between about 0.5-1.0 psi, preferably about 0.98 psi, are desired
and considered acceptable to provide atraumatic contact between the
patient P and the apparatus 200 when a force of 3 pounds is applied
normal to a surface of the patient for approximately one hour. It
should be understood that a variety of different sized
tissue-engaging surfaces 220 may be used depending on the amount of
time and force applied during a particular interventional
procedure. Referring to FIG. 5A, the area of the tissue-engaging
surface 220 of the base 210 may be altered by using a variety of
different sized elastomeric cushions 222 with the rigid plate 215
of the base 210. As noted above, the tissue-engaging surface 220 of
the support apparatus 200 preferably has a surface area of at least
about 3 square inches, more preferably at least 4 square inches,
and most preferably at least 5 square inches.
In a preferred embodiment, clamp assembly 212, as shown in FIGS. 5A
and 6A, comprises a first jaw 230 and a second jaw 232. The pair of
jaws are typically opposed to one another and are typically
rotatably mounted on a segment 233 of L-shaped arm 214 generally
parallel to the base 210. Clamp aperture 235 (FIG. 6D and 6E) and
segment 233 act as a rotational linkage. This rotatability allows
the clamp assembly 212 to engage the retractor 40 at a plurality of
angles from which the retractor may extend from the body cavity
(FIG. 7B). It should be understood that a variety of other devices
known in the art may be used to rotatably couple the clamp assembly
212 to the arm 214.
Both the first jaw 230 and second jaw 232 have a retractor or tool
engaging surface 234. The opposing jaws, in addition to being
rotatable, are also axially translatable on the segment 233. A
spring 236 such as a coil spring keeps the jaws apart when the
clamp assembly is not engaging retractor 40. An axial translation
limiter 238 coupled to the clamp assembly, such as a set screw,
allows slidable axial translation but prevents the complete
disengagement of the jaws 230 and 232 from the spring 236. The
limiter 238 facilitates alignment between the jaws 230 and 232 so
that they mate accurately. The spring 236 facilitates engagement of
clamp assembly 212 with the retractor 40 by keeping the jaws apart
prior to closing of the clamp assembly. It should be understood
that a variety of different clamp assemblies may be used so long as
the retractor can be releasably engaged and rotate about an axis
typically parallel to the rigid plate of the base 210.
A variety of different closure devices may be used to close and
engage the clamp assembly 212 with the retractor 40. FIGS. 5A and
6A show a thumb-screw 240 threaded on the horizontal rod or segment
233 (FIG. 5C) of arm 214. Alternatively, a cam-release device 250
as shown in FIGS. 6B and 6C maybe pivotally attached to distal end
of generally horizontal segment of arm 214 to provide closing of
the jaws 230 and 232.
As shown more clearly in FIGS. 6C, each jaw 230 and 232 of the
clamp assembly 212 has a protrusion 252 to facilitate alignment of
the jaws 230 and 232 when the clamp assembly is closed. Both the
protrusions 252 are typically machined into the inside, opposing
faces of the jaws 230 and 232. An exemplary embodiment of jaws of
the clamp assembly 212 are shown in FIGS. 6D and 6E. First
integrated jaw 254 and second integrated jaw 256 have protrusions
258 and 260 formed with the jaws for facilitating alignment during
closure of the assembly 212. First, outer protrusions 258 fit over
the second, inner protrusions 260 when the jaws are engaged.
Second, inner protrusions 260 have a surface 262 which generally
conforms with the horizontal, preferably rod-shaped segment 233 of
the arm 214 to facilitate sliding translation of the second jaw
256.
Overtightening surfaces 264 and 266 on the jaws 254 and 256 prevent
complete closure of retractor engagement surfaces 234 which may
damage the retractor 40. Alternatively, retractor engagement
surface 234 may be coated with an elastomeric material such as
silicone to improve frictional contact between the retractor and
the clamp assembly 212. The covering (not shown) may also prevent
crimping damage which would likely result if the clamp assembly 212
is overtightened on the retractor 40. Holes 268 on surfaces 264 and
266 are provided for engaging the set screw 238.
Referring now to FIG. 7A, the system 300 for manipulating tissue
structure in the thoracic cavity comprises a retractor 40 and the
tool support apparatus 200. Once coupled to the apparatus 200, the
shaft 39 of the retractor 40 acts as a linking member between the
contact surface 502 on tissue supporting member 500 and the
tissue-engaging surface 220. The surfaces 220 and 502 act like a
clamp to reposition tissue in a body cavity while pressing against
typically a outer surface of the patient or body cavity. Clamp
assembly 212 on the apparatus 200 is used to secure the apparatus
220 to the retractor 40. It should be understood that although in
the preferred embodiment the tool support apparatus 200 is
removably coupled to the retractor 40, alternate embodiments of the
system 300 may comprise a retractor 40 that may be slidably but
undetachably coupled to the support apparatus 200.
Referring to FIG. 7B, the ability to rotate the clamp assembly 212
on segment 233 (FIGS. 5A and 5C) allows the apparatus 200 to engage
shaft 39 of the retractor 40 when the shaft does not exit a body
cavity, such as the thoracic cavity TC, at a normal angle. This
aspect of the present invention allows support apparatus 200 to
position the tissue support member 500 at a variety of angles to
best provide access and line of sight to the area of surgical
intervention.
A method for manipulating tissue structure using system 300 will
now be described with reference to FIGS. 8-10. The method comprises
introducing a tissue positioning tool such as the retractor 40
having shaft 39 (FIG. 7A) within the thoracic cavity through a
percutaneous penetration. The tool or retractor 40 may be assembled
within the thoracic cavity TC as shown in FIG. 8. The tool may also
be introduced through trocar 24 or alternatively through a
percutaneous puncture without the trocar (FIG. 9). In certain
scenarios, it is necessary to introduce individual portions of the
tissue positioning tool 40 through first and second percutaneous
penetrations in the thoracic cavity. FIG. 8 shows the retractor 40
inserted through trocar 24 while tissue supporting member 500 is
inserted through trocar 22. The distal tip 41 of the retractor 40
may be threaded or otherwise adapted to be releasably coupled to
the tissue supporting member 500. The retractor 40 is coupled to
the member 500 and is now ready to engage the tissue surface (FIG.
9). It should be noted that the tool support apparatus 200 may be
connected to shaft 39 of the retractor 40 either prior to inserting
the retractor 40 into the trocar 24 or anytime thereafter.
With the tool or retractor 40 ready to engage the tissue structure
such as the atrium wall AW of the left atrium LA, force is applied
to the shaft of the tissue positioning tool to retract the tissue
structure. FIG. 9 shows the system 300 where the tissue supporting
member 500 and the retractor 40 have been introduced into the
thoracic cavity and positioned to maintain a force against the
tissue structure of the patient's heart. This force, typically
between about 1-3 lbs, provides retraction that opens the line of
sight and access to the mitral valve MV. Once the tool or retractor
40 is in position, the tool support apparatus 200 may be positioned
or repositioned along the shaft 39. Adjustments are then made to
engage or close the clamp assembly 212 on the support apparatus 200
with the shaft 39. This may involve tightening a thumb-screw,
pulling on a release lever, or using other known methods of
closure. By pressing against a surface of the patient such as the
outer surface of the chest, the apparatus 200 can position the
retractor 40 and maintain the retractive force on the retractor as
required to provide line of sight and open access to the mitral
valve MV. FIG. 9 shows an optional aspect of the method where the
trocar 24 is not used with the retractor 40 through the
percutaneous intercostal penetration. FIG. 10 provides an alternate
view of the apparatus 200 engaged to the retractor 40 and resting
on the chest of a patient. Although the drawings show the retractor
40 positioned at an angle normal to the surface of the patient, it
should be understood that the apparatus 200 can engage and position
the retractor 40 at a variety of other different angles.
Referring now to FIGS. 11A and 11B, alterative embodiments of the
tool support apparatus 200 will be described. In FIG. 11A, the
first alternate support apparatus 600 comprises of a first
alternate base 602 having an aperture 603 and a carriage 604 for
rotatably supporting an engagement assembly 606 to base 602. A
shaft (not shown) extending between the carriage 604 has a user
interface 608 that provides rotational positioning for the
engagement clamp assembly 606. A set screw 610 provides frictional
engagement with a retractor 40.
FIG. 11B illustrates a second alternate support apparatus 650 which
has a second alternate base 652 having an aperture 654. The base
652 is removably coupled to an engagement assembly 656 which is
removably coupled to base 652. The base has a tongue 657 for
releasably engaging groove 658 on engagement assembly 656.
Engagement assembly 656 has an engagement surface 659 which is
rotatable about an axis horizontally parallel to the base 652. A
screw-type tightening device 660 can be used to engage a second,
opposing engagement surface (not shown) against engagement surface
659 to hold a retractor 40 therebetween. The apparatus of the
present invention may have a variety of different embodiments so
long as the apparatus has a base of sufficient surface area to
prevent trauma to the patient, an aperture or open space for
accommodating the retractor 40, and a clamp assembly that can
engage a tool and rotate about an axis generally horizontal to the
base.
A tool support apparatus 200 according to the present invention may
be packaged together with instructions for use (IFU) in a kit as
shown in FIG. 12. A conventional package, which may be a pouch 700
or any other suitable package, such as a tray, box, tube, or the
like, may be used to contain the apparatus 200 and IFU 710, where
the IFU may be printed on a separate sheet and/or may be printed on
the packaging itself. The kit may also include a retractor 40 which
may be permanently or releasably coupled to the apparatus 200.
Optionally, but not necessarily, the tool support apparatus 200
and/or the retractor 40 may be sterilized within the package, e.g.
by radiation or ethyleneoxide. The instructions will set forth any
of the aspects of the method of the present invention described
above.
Although the foregoing invention has been described in some detail
by way of illustration and example, for purposes of clarity of
understanding, it will be obvious that certain changes and
modifications may be practiced within the scope of the appended
claims.
* * * * *